The need to efficiently conduct cryogenic fluids in such applications as particle accelerators, superconductive material applications etc. has spawned the development of numerous cryogenic fluid conduit designs. While these prior art designs have apparently been successful in achieving successful transfer of cryogenic fluids, they have demonstrated certain shortcomings. Most notably, these shortcomings related to flexibility and cost as reflected in the difficulty to manufacture. While flexibility has been achieved in some designs, it has normally been at a significant manufacturing cost penalty.
An example of such a flexible cryogenic conduit is described in U.S. Pat. No. 4,492,089 to Rohner et al issued Jan. 8, 1985. This patent describes a cryogenic conduit consisting of two concentric corrugated tubes having a series of five wound members therebetween. The wound members consist of a plurality of metallic ribbons having conduits for coolant welded thereto, a helical spacer and several layers of "super insulation". The entire assembly is finally covered with a thermoplastic envelope or jacket. While such a structure may prove adequate for the transfer of cryogenic fluids, its flexibility is significantly impaired by its structure, but more importantly, the manufacture of the metallic ribbons with conduit welded thereon is extremely expensive and will render the cost of the conduit extremely high.
Other cryogenic conduit devices are disclosed in U.S. Pat. Nos. 4,344,462, 3,706,208, and 4,380,253.